A lack of career guidance in school and general pressures on students in sixth year have been highlighted as among the main reasons for picking the wrong third-level course.

A new report also points a finger at college marketing strategies and how well course content and the demands of a programme are explained to potential applicants,

Dropping out off college can be distressing for students, costly for families and are a drain on State resources.

It is most likely to occur in first year, and, on average, 15pc of college entrants - about one in seven - abandon their course, amounting to about 7,000 freshers every year. The highest rate, 22pc, is found in institutes of technology, while in the universities it is 9pc.

Now, for the first time, comprehensive research provides insights into why these students, having accepted a place, do not stick with it.

The 'Why Do Students Leave Higher Education' study was carried out by Professor Suzanne Quin, Dr Niamh Moore-Cherry and Dr Elaine Burroughs, at University College Dublin, for the National Forum for the Enhancement of Teaching and Learning.

Their findings are based on data provided by 4,036 students in universities, institutes of technology and private colleges, who left their third-level courses between 2011 and 2014.

Slightly more than half of those, 2,042, cited the course as the key reason for their withdrawal, way ahead of the next biggest categories: personal, financial, health/medical and family.

Among the 51pc who gave the course as the reason, most said it was simply the wrong choice. Others cited course difficulty, that the course did not meet their expectations, making a mistake with the CAO, or not getting their top CAO choice.

According to the authors, "wrong course choice is a recurring theme needing multiple approaches to ensure that second-level students are best prepared for making informed decisions when completing their CAO application form".

They state that "although many students were offered the course they had chosen through the CAO process, the issue is that they made the wrong choice at application stage".

The report notes that most students decide about their CAO choices when they are under pressure with mock and final state examinations, which "can lead to students making uninformed or rushed decisions".

And, linked to that, students indicated a perception that they had inadequate guidance in making their choices, with some stating that they were not fully informed about the requirements of the course.

The authors call for a fresh approach to the issue of student withdrawal and, among their recommendations, are that colleges make clear the course content and demands, and whether the minimum requirements are pitched at a sufficiently high level to ensure that those on the margin can cope.

Meanwhile, 39,832 of the 52,058 CAO applicants who received a round-one offer last week have accepted it. CAO round two offers will be released on Thursday.